Brushless Motor Choices

[stevet]

I am converting my Cinestar 3 axis gimbal with servos and Radians to brushless and need some advice on gimbal motors. I haven't ordered the gimbal parts yet but I have just received 2 BLD modules from John and I am planning the rest of the conversion. There are a number of options and descisions to be made and I wondered what conclusions others had come to.

I see Kopterworx have an upgrade kit that includes the iflight 5208 motors. Brushless Gimbals(.com) have a similar conversion kit that provide a number of motor options ranging from the iflight 8017 motor, the Tiger 8106 and Tiger GB85 but actually recommend somewhere on their site a mixture of these motors on the pan and roll/tilt for best results.

There is quite a difference in price and more importantly weight of these motors (ranging from 168g to over 300g for the largest motor) The brushlessgimbal.com site refers to the Epic for the larger motors and I am assuming that the 5208 might be suitable for the GH2/3.

John Cunningham elsewhere here has reported that his 5108 pan motor is good for stabilisation but marginal during panning.

All of the above info has left me seeking further assistance particularly regarding the motor selection. I am initailly interested in using a Panasonic GH3 probably with the very light 20mm/1.7 lens so I am assuming that the 5208 motors would be adequate but may require a different motor in pan. If that is the consensus thought for tilt and roll can someone also advise what is the difference in the 150 turn version of the 5208 and 180 turn model.

Many thanks Steve

[higheye]

HI Steve:
I don't have your answers...just interested that we appear to be at the same point , on the same path, with the same concerns ( almost like a parallel universe)
Because of the problems of balancing with various cameras,I have decided to start from scratch with a new BL gimbal, and retain the original one to use for still images. I have a SONY 760 , which weighs in at about 700 g The 5208 , from what I can find , has 1.7kg of torque this sounds like it would be OK for the Tilt and Roll, but I am concerned about the pan. In a perfect world with the copter hovering level , and a perfectly balanced gimbal, again, probably OK,.... but if the copter is maneuvering, and not level, this would ( I believe)cause the gimbal motor to work harder.

I am also interested in what others have come up with

Murray Hunt

[stevet]

Hi Murray

Thank you for your thoughts. I have started down the road to adapt my CS3 gimbal and I have purchased 3 5208 motors. The kit I have purchased simply replaces the pan and roll servos with two of the 5208 motors so still actually relies on each pulley there but the tilt motor is direct drive. I am told that this system will be good for my intended use with the GH3. I haven't put it all together yet due to paid work getting in the way!! I am advised that actually there are some advantages in using the existing pulleys and the new motors in this way. Gearing is obviously one advantage with these relatively light weight motors but also rotation of the motor distributing the wear of the motor does make a lot of sense, which otherwise would be concentrated in a very limited area.

In the meantime, whilst waiting for all of this kit I have had second thoughts and coincidently I was considering your approach Murray and that is a to build a new gimbal. Having the original CS3 alongside me on my desk and looking at the parts I would need it seemed like a sensible alternative. So by DHL today the relevant parts from brushlessgimbals.com have arrived. I have gone for their deluxe conversion kit with a 8017 motor for the pan and two 5108 motors for roll and tilt, all direct drive. I am still going to try the three 5208's first with two of the existing pulleys which is going to be a lot lighter than the second option. Indeed it may actually be better with a lighter load and adequate for my purpose. If that is the case then my second option will be put to good use as a hand held rig. Had the pleasure yesterday on a job in London, seeing how the pro's were using their new Movi with a Epic hand held. I was there just doing the stills for the client. That Movi just does not look 15k, especially after receiving the blgimbals stuff which does look very high quality. That combined with some 25mm dia CF tube for £17 per 500mm, I am hoping to build something special for all of my hand held work at a fraction of the cost.

I nearly bought separately the brushlessgimbals pan motor cage to use with option one. There was one for sale on MRF. The seller was keeping the 8017 motor he bought with it, but needed the pulley version for the pan. Interestingly even that motor was not adequate direct drive for what he was carrying, an Epic. I bit out of my league but I can see that the pan requirement needs careful consideration. Anyway I will let you know how I get on.

Steve.

[katya]

We have been using G-lock brushless module on all 3 axis of a CS gimbal brushless conversion with 5208 180T on each access, no pulleys, direct drive. We are flying Black Magic Pocket Cinema camera with RT Motion follow focus and 9-18mm lens. AUW of gimbal is 3.4 kg and we have had great results with all axis, roll and tilt hold brilliantly and the pan works great so long as you don't try and do a whip pan! If you want fast moves on the pan then I think you would need a higher torque motor. Look forward to hearing your thoughts on different motors and camera combos:-)
Kat

[stevet]

Hi Kat

Yes I am look forward to it too. Just a minor point but the motors I have are the same but 150T. A few less turns, not sure whether it will make any difference. Your set up sound good and I have very pleased. I think the lightweight conversion kit I have purchased also uses pulleys (except for tilt) because very few parts are actually required which actually makes the conversion inexpensive. Steve